High titers of interferon (IFN) induced by Poly ICLC correlate with enhanced macrophage (M0) and Natural Killer Cell (NKC) tumor lytic activity (TLA). Poly ICLC combined with Cytoxan cytoreductive therapy results in a synergistic antitumor effect. Bone marrow cell (BMC) depression resulting from irradiaton or cytoreductive treatment is reversed by Azimexon treatment through stimulated proliferation of nucleated BMC and colony stimulating factor (CSF). Lipopolysaccharide, Poly ICLC and IFN stimulate cellular secretion of CSF. Suppression of the delayed type hypersensitivity response (DTHR) by human chorionic gonadotropin was abrogated by indomethacin and aspirin indicating suppression is mediated through prostaglandin. Enhanced DTHR achieved with 6 biological response modifiers (BRMs): Levan, Lentinan, Mannozym, MVE2, Poly ICLC, IFN, was correlated with their capacity to regulate M0 and NKC TLA. Significant therapeutic response was achieved against an alveolar lung Ca with combined cytoreductive chemotherapy and MVE. Pharmacokinetic studies of BRMs indicated that treatment scheduling is critical in regulating M0 and NKC TLA.